1. Field of the Invention
The present invention relates to a control apparatus for a hydraulic excavator.
2. Description of the Related Art
The hydraulic excavator is provided, as working equipment for work, with an engine and a hydraulic pump driven by the engine, and further provided with hydraulic actuators (hydraulic cylinders) for driving a boom, an arm and a bucket of the hydraulic excavator, hydraulic actuators (hydraulic motors) for swing and travel, and the like. In work, operating levers corresponding to the hydraulic actuators are operated so that working fluid is supplied from a hydraulic pump to the hydraulic actuators whereby the hydraulic actuators are actuated to perform various works.
Works to be done by the hydraulic excavator include various classications of works such as a scattering work, a compacting work, a slope finishing work, a crane work, a digging work, a loading work, a finishing with swing, etc., the digging work including such classifications of works as a digging with swing, a simple digging work, a ditch digging work, a horizontal digging work, etc. In these works, since the motion and the load state of the hydraulic excavator as required are often different, it is preferred that working equipment such as an engine and a hydraulic pump be operated in the precise operating mode corresponding to these classifications of works.
For example, the digging work is generally high in load as compared with other works. It is therefore preferred that the engine and the hydraulic pump be controlled so that a sufficient driving force of the engine may be transmitted to the hydraulic actuators through the hydraulic pump. Conversely, the crane work and the loading work are low in load, and a large driving force of the engine is not necessary. It is therefore preferred that the engine and the hydraulic pump be controlled so as to reduce a fuel consumption of the engine as small as possible.
On the other hand, in a conventional hydraulic excavator so far known, for example, an engine speed can be regulated by a work of an operating mode switch by an operator to regulate an absorbing rate (a so-called absorbing horse power of a hydraulic pump) of a driving force (an output) of the engine into a plurality of classifications of works by a hydraulic pump whereby the work of the hydraulic excavator adapted for the kind of work can be performed.
As an alternative proposal so far known, when work stops at which all operating levers are in a neutral position, if an operator operated a predetermined switch in advance, an engine speed is automatically controlled to a predetermined low engine speed to thereby reduce a fuel consumption of the engine.
However, in the conventional hydraulic excavator as described above, for performing the work of the hydraulic excavator adapted to the kind of work as intended by an operator, it is necessary for the operator himself to discriminate its kind of work from other classifications of works and perform a predetermined switch work. For this reason, the operator often forgets the switch work so that the switch work is not performed. In such a case, there poses an inconvenience that the work of the hydraulic excavator adapted to the kind of work cannot be performed, and capability of the hydraulic excavator cannot be drawn sufficiently. Further, even if in a certain work, an operator performs the switch work, he often forgets, when the other kind of work is performed, to release the switch work. In such a case, there poses an inconvenience that an operator cannot perform the work of the hydraulic excavator as desired.
Furthermore, another hydraulic excavator of this kind has been known in which a so-called hour-meter for counting and recording the operating time of the engine for the hydraulic excavator is mounted for purposes of a personnel management of operators (grasping of labor time, decision of wages, etc.) and a maintenance management of the hydraulic excavator or an assessment of price of used excavators, etc.
However, since the hour-meter is provided merely for counting and recording the operating time of the engine, the time during which an operator takes a rest while the engine is being operated is also counted, failing to properly grasp actual labor time of an operator from the recorded content of the hour-meter. Moreover, the content of work done by the hydraulic excavator cannot be known from the recorded content of the hour-meter, thus failing to grasp whether or not the content of work participated by operators is one which requires a high degree of skill, for example. Accordingly, it is difficult to properly perform the personnel (labor) management of operators from the recorded content of the hour-meter.
Further, in performing maintenance of parts-replacement of a hydraulic excavator, a hydraulic excavator by which a heavy load work, for example, such as digging work, is frequently performed is greatly different from a hydraulic excavator by which a light load work such as a finishing work is frequently performed in locations and time at which apparatuses wear or deteriorate. For this reason, even if the locations and time at which maintenance of the hydraulic excavator is performed are decided on the basis of the operating time of the engine merely recorded on the hour-meter, it is difficult to perform the proper maintenance with respect to the individual hydraulic excavators having multifarious working records.
Further, since the time and locations at which apparatuses wear or deteriorate are different according to the content of work done by the hydraulic excavator, as mentioned above, even if the assessment of price of used hydraulic excavators is made on the basis of the operating time of the engine merely recorded on the hour-meter, it has been difficult to make a proper assessment of price.
For solving the problems as noted above, a discrimination of classifications of works of a hydraulic excavator is a first factor. It is a first object of the present invention to provide an apparatus for detecting operating amounts of operating levers and discriminating classifications of works merely from the operating amounts, without adding a special sensor.
It is a second object of the present invention to provide a control apparatus for a hydraulic excavator capable of performing a precise work according to various discriminated classifications of works, without requiring an switch operation by an operator.
It is a third object of the present invention to provide a control apparatus for a hydraulic excavator capable of properly performing a personnel management of operators and a maintenance management of a hydraulic excavator or an assessment of price of used excavators in consideration of working records of the hydraulic excavator.